torres engineering tube rec. kit

[MitchK]

Has anyone ever ordered one of these kits? I'm not sure what to think of the torres site, everything looks really cheap. But I have a peavey 5150 that I'd like to try this tube rectifier mod on.

My other question is about the voltage. The 5150 has a full bridge rec in it now, but if I switch to a tube rec, won't that decrease the voltage coming out of rectifier by quite a bit? hows that going to effect my sound? I thought about just making it switchable so I can leave what in there for the moment and have the tube rec as something I can switch to if i want that sound. just not sure if its worth it...

[Enzo]

Where will you get the center tap for the transformer winding? That winding was designed for the full bridge. If you grounded it you could get half wave rectification. that would be awful hummy.

[Schwalbe]

There are a couple of places that will not get my business, That is one of them. Proceed with caution. Google the company name.
YMMV

[MitchK]

this is what I'm unsure of because I don't know what the kit comes with. I'm fairly sure a transformer is included in the kit, not a new power transformer obviously, but a small one for..... and this is what I can't really figure out.

[Satamax]

Mitch, why don't you make it yourself???

A tube socket, a tube recto, some wire, a 110/220V>5 volts trany, of about 30 VA, and two 1N4007 or BY427 (or whatever you have in your amp for the full bridge) and you're done, you keep the two negative legs of your bridge recto as they are solid state diodes, and replace the two positive ones by the tube recto. Done.

Bye.

Max.

[Ray Ivers]

Mitch,

If you simply add a small-value power resistor - say, 47 ohms, 5 watt to start - between your HV bridge rectifier's output and the first filter caps (C34/C38 on my print), IMO you will obtain 90% or more of the sonic effect of a tube rectifier at an absolute minimum of expense, complexity, and risk. If you want more 'tube-rectifier effect', just increase the resistor value.

If you're not happy with the results, just reconnect your bridge and you're back to stock; no harm, no foul, and no holes.

Ray

[Thorny]

Say no to anything Torres that involves amp mods - my opinion and a lot of others. You would need a transformer to supply the 5v for the rectifier tube, so it would have to include a transformer to add on just for that. Yes it would decrease your voltage - that is most of the point. In that amp, I am not sure what the point would be really as a decrease in voltage should require a rebias as well (or it would be off).

If you have the head version and haven't done the bias mod DO THAT! It makes the amp SO MUCH BETTER. Also, put a good solid set of output tubes in it - no sovtek 5881s or the really cheap shuguangs (the good shuguangs are recommended). Also, good preamp tubes that handle high gain but are not harsh - JJ comes to mind. Then when you put the adjustable bias in and actually bias the amp correctly it will sound like a million bucks. The clean tone will even sound pretty good. That is the best mod you can do - and it is inexpensive to.

If you set the bias and subsequently lowered the voltage with a tube rec, it would just throw the bias off again.

[Satamax]

I like the reply from Thorny, no sovtek 5881 Well, waffer base ones from radio (6P3SE) which i think sovtek use to sell, can be amazing just bias them with EL34 voltages instead of 6L6 voltages I had some in a laney 50 watts, modern ones, with toroidal trany, biassed for EL34, and ouch, what a sound it was running the tubes 30,2 watts at iddle and it's been like this ever since, which is a good while ago, and that amp belongs to a gigging musician, not to me! So 5881 can be good

[Enzo]

The kit transformer will be there to provide the 5v for the tube rectifier heater. The tube recto kit allows you to replace some split winding solid state diode pair with a rectifier tube. But the 5150 doesn't HAVE a split winding. THAT will be the hang up.

[Analog Assassin]

What about a Weber copper cap rectifier? It's supposed to give the voltage drop and sag of a tube rectifier, but you just solder it in the amp, no transformer or tube.

[MitchK]

Hmm I definitely think I'll experiment with a resistor like ray said or the copper cap, that will be good enough for me, I basically am just looking for stuff to do to this thing and see what I can get out of it. I'm planning on putting in an another EQ circuit so the different channel can have their own, and I've already rebiased it and yes it makes a huge difference. I've been planning on new pre-tubes and did have JJs in mind but just haven't gotten around to doing it yet for some reason. I was actually just running a pair of KT88s in it up until last night when one of them decided to die on me (my own fault though I was running the bias too hot). Almost a bit a of a relief though, the KT88s were just too bright the amp would feedback at high volumes. perhaps there is something I can do about this though, because I did like the characteristics of the kt88.

really if anyone has any other ideas of things I can do to toy around with this let me have it. I was thinking about trying to make the crunch on the clean channel footswitchable. I don't want to get into a midi connector so I was thinking about just another 1/4 jack like the other switch and just physically tie them together hahaha.

once again thanks for the input guys, it actually means a lot to me I'd be in the dark without this stuff.